Confusing Translations and Rotations with Reflections

submitted by: Rebecca Peterson
on Mon Nov 7 21:25:24 2005

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Course: Geometry
Topic: Transformations
Resource type: Activity
Catalogue entry:,10.13,ALL,ALL/
Resource location:

I am a student at USU going into Math/Stat Education. In a class for learning about applying Technology to teaching Math, I had the opportunity to teach about transformations of objects in a middle school in Cache Valley. I taught the students using an eNLVM lesson about translations and a bit about rotations.

The lesson focused on the idea of a translation being two reflections over two parallel lines. It also stated that a rotation is two reflections over two non-parallel lines. The activities were based on this idea and having students translate or draw translations. Also, the students were taught how to calculate angles of rotation by multiplying the angles made by the non-parallel lines by 1/2. The idea for teaching rotations and translations was new to me. It is an interesting way to understand the transformations, and could be very helpful to students.

During the lesson the students seemed to want to play and talk to their neighbors more than focus on the lesson. This could be due to the fact that they are 14 and 13. But I think that the lesson just wasn't engaging. The students found no value in what they were doing and got bored quickly. Also, the eNLVM server had been down the day before and it was very slow and took a long time to upload the applets involved.

I found that most of the students had a hard time understanding that both rotations and translations were reflections. I think the concept was a bit abstract and that the students couldn't follow it. The students really just wanted to fool around instead of completely understanding the material presented. I think the lesson would be more interesting if the students could see how it applied. The students were very engaged in the “Create Wallpaper” section of the translations lesson. They enjoyed seeing the tessellations in the plane by translations and how they could tessellate crazy objects as long as it stayed with in certain limitations of angles.

Over all, I think the web lesson design needs to be revised and suited more to activities that will engage students and allow them to understand rotations and translations in simpler less ambiguous terms. Math is wonderful and shouldn't be bogged down by too much technology; it should be aided by technology.

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Mon Nov 7 21:25:24 2005